2 * linux/kernel/irq/manage.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
7 * This file contains driver APIs to the irq subsystem.
10 #include <linux/irq.h>
11 #include <linux/kthread.h>
12 #include <linux/module.h>
13 #include <linux/random.h>
14 #include <linux/interrupt.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
18 #include "internals.h"
21 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
22 * @irq: interrupt number to wait for
24 * This function waits for any pending IRQ handlers for this interrupt
25 * to complete before returning. If you use this function while
26 * holding a resource the IRQ handler may need you will deadlock.
28 * This function may be called - with care - from IRQ context.
30 void synchronize_irq(unsigned int irq
)
32 struct irq_desc
*desc
= irq_to_desc(irq
);
42 * Wait until we're out of the critical section. This might
43 * give the wrong answer due to the lack of memory barriers.
45 while (desc
->istate
& IRQS_INPROGRESS
)
48 /* Ok, that indicated we're done: double-check carefully. */
49 raw_spin_lock_irqsave(&desc
->lock
, flags
);
51 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
53 /* Oops, that failed? */
54 } while (state
& IRQS_INPROGRESS
);
57 * We made sure that no hardirq handler is running. Now verify
58 * that no threaded handlers are active.
60 wait_event(desc
->wait_for_threads
, !atomic_read(&desc
->threads_active
));
62 EXPORT_SYMBOL(synchronize_irq
);
65 cpumask_var_t irq_default_affinity
;
68 * irq_can_set_affinity - Check if the affinity of a given irq can be set
69 * @irq: Interrupt to check
72 int irq_can_set_affinity(unsigned int irq
)
74 struct irq_desc
*desc
= irq_to_desc(irq
);
76 if (!desc
|| !irqd_can_balance(&desc
->irq_data
) ||
77 !desc
->irq_data
.chip
|| !desc
->irq_data
.chip
->irq_set_affinity
)
84 * irq_set_thread_affinity - Notify irq threads to adjust affinity
85 * @desc: irq descriptor which has affitnity changed
87 * We just set IRQTF_AFFINITY and delegate the affinity setting
88 * to the interrupt thread itself. We can not call
89 * set_cpus_allowed_ptr() here as we hold desc->lock and this
90 * code can be called from hard interrupt context.
92 void irq_set_thread_affinity(struct irq_desc
*desc
)
94 struct irqaction
*action
= desc
->action
;
98 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
99 action
= action
->next
;
103 #ifdef CONFIG_GENERIC_PENDING_IRQ
104 static inline bool irq_can_move_pcntxt(struct irq_desc
*desc
)
106 return desc
->status
& IRQ_MOVE_PCNTXT
;
108 static inline bool irq_move_pending(struct irq_desc
*desc
)
110 return irqd_is_setaffinity_pending(&desc
->irq_data
);
113 irq_copy_pending(struct irq_desc
*desc
, const struct cpumask
*mask
)
115 cpumask_copy(desc
->pending_mask
, mask
);
118 irq_get_pending(struct cpumask
*mask
, struct irq_desc
*desc
)
120 cpumask_copy(mask
, desc
->pending_mask
);
123 static inline bool irq_can_move_pcntxt(struct irq_desc
*desc
) { return true; }
124 static inline bool irq_move_pending(struct irq_desc
*desc
) { return false; }
126 irq_copy_pending(struct irq_desc
*desc
, const struct cpumask
*mask
) { }
128 irq_get_pending(struct cpumask
*mask
, struct irq_desc
*desc
) { }
132 * irq_set_affinity - Set the irq affinity of a given irq
133 * @irq: Interrupt to set affinity
137 int irq_set_affinity(unsigned int irq
, const struct cpumask
*mask
)
139 struct irq_desc
*desc
= irq_to_desc(irq
);
140 struct irq_chip
*chip
= desc
->irq_data
.chip
;
144 if (!chip
->irq_set_affinity
)
147 raw_spin_lock_irqsave(&desc
->lock
, flags
);
149 if (irq_can_move_pcntxt(desc
)) {
150 ret
= chip
->irq_set_affinity(&desc
->irq_data
, mask
, false);
152 case IRQ_SET_MASK_OK
:
153 cpumask_copy(desc
->irq_data
.affinity
, mask
);
154 case IRQ_SET_MASK_OK_NOCOPY
:
155 irq_set_thread_affinity(desc
);
159 irqd_set_move_pending(&desc
->irq_data
);
160 irq_copy_pending(desc
, mask
);
163 if (desc
->affinity_notify
) {
164 kref_get(&desc
->affinity_notify
->kref
);
165 schedule_work(&desc
->affinity_notify
->work
);
167 irq_compat_set_affinity(desc
);
168 irqd_set(&desc
->irq_data
, IRQD_AFFINITY_SET
);
169 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
173 int irq_set_affinity_hint(unsigned int irq
, const struct cpumask
*m
)
175 struct irq_desc
*desc
= irq_to_desc(irq
);
181 raw_spin_lock_irqsave(&desc
->lock
, flags
);
182 desc
->affinity_hint
= m
;
183 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
187 EXPORT_SYMBOL_GPL(irq_set_affinity_hint
);
189 static void irq_affinity_notify(struct work_struct
*work
)
191 struct irq_affinity_notify
*notify
=
192 container_of(work
, struct irq_affinity_notify
, work
);
193 struct irq_desc
*desc
= irq_to_desc(notify
->irq
);
194 cpumask_var_t cpumask
;
197 if (!desc
|| !alloc_cpumask_var(&cpumask
, GFP_KERNEL
))
200 raw_spin_lock_irqsave(&desc
->lock
, flags
);
201 if (irq_move_pending(desc
))
202 irq_get_pending(cpumask
, desc
);
204 cpumask_copy(cpumask
, desc
->irq_data
.affinity
);
205 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
207 notify
->notify(notify
, cpumask
);
209 free_cpumask_var(cpumask
);
211 kref_put(¬ify
->kref
, notify
->release
);
215 * irq_set_affinity_notifier - control notification of IRQ affinity changes
216 * @irq: Interrupt for which to enable/disable notification
217 * @notify: Context for notification, or %NULL to disable
218 * notification. Function pointers must be initialised;
219 * the other fields will be initialised by this function.
221 * Must be called in process context. Notification may only be enabled
222 * after the IRQ is allocated and must be disabled before the IRQ is
223 * freed using free_irq().
226 irq_set_affinity_notifier(unsigned int irq
, struct irq_affinity_notify
*notify
)
228 struct irq_desc
*desc
= irq_to_desc(irq
);
229 struct irq_affinity_notify
*old_notify
;
232 /* The release function is promised process context */
238 /* Complete initialisation of *notify */
241 kref_init(¬ify
->kref
);
242 INIT_WORK(¬ify
->work
, irq_affinity_notify
);
245 raw_spin_lock_irqsave(&desc
->lock
, flags
);
246 old_notify
= desc
->affinity_notify
;
247 desc
->affinity_notify
= notify
;
248 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
251 kref_put(&old_notify
->kref
, old_notify
->release
);
255 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier
);
257 #ifndef CONFIG_AUTO_IRQ_AFFINITY
259 * Generic version of the affinity autoselector.
262 setup_affinity(unsigned int irq
, struct irq_desc
*desc
, struct cpumask
*mask
)
264 struct irq_chip
*chip
= irq_desc_get_chip(desc
);
265 struct cpumask
*set
= irq_default_affinity
;
268 /* Excludes PER_CPU and NO_BALANCE interrupts */
269 if (!irq_can_set_affinity(irq
))
273 * Preserve an userspace affinity setup, but make sure that
274 * one of the targets is online.
276 if (irqd_has_set(&desc
->irq_data
, IRQD_AFFINITY_SET
)) {
277 if (cpumask_intersects(desc
->irq_data
.affinity
,
279 set
= desc
->irq_data
.affinity
;
281 irq_compat_clr_affinity(desc
);
282 irqd_clear(&desc
->irq_data
, IRQD_AFFINITY_SET
);
286 cpumask_and(mask
, cpu_online_mask
, set
);
287 ret
= chip
->irq_set_affinity(&desc
->irq_data
, mask
, false);
289 case IRQ_SET_MASK_OK
:
290 cpumask_copy(desc
->irq_data
.affinity
, mask
);
291 case IRQ_SET_MASK_OK_NOCOPY
:
292 irq_set_thread_affinity(desc
);
298 setup_affinity(unsigned int irq
, struct irq_desc
*d
, struct cpumask
*mask
)
300 return irq_select_affinity(irq
);
305 * Called when affinity is set via /proc/irq
307 int irq_select_affinity_usr(unsigned int irq
, struct cpumask
*mask
)
309 struct irq_desc
*desc
= irq_to_desc(irq
);
313 raw_spin_lock_irqsave(&desc
->lock
, flags
);
314 ret
= setup_affinity(irq
, desc
, mask
);
315 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
321 setup_affinity(unsigned int irq
, struct irq_desc
*desc
, struct cpumask
*mask
)
327 void __disable_irq(struct irq_desc
*desc
, unsigned int irq
, bool suspend
)
330 if (!desc
->action
|| (desc
->action
->flags
& IRQF_NO_SUSPEND
))
332 desc
->istate
|= IRQS_SUSPENDED
;
340 * disable_irq_nosync - disable an irq without waiting
341 * @irq: Interrupt to disable
343 * Disable the selected interrupt line. Disables and Enables are
345 * Unlike disable_irq(), this function does not ensure existing
346 * instances of the IRQ handler have completed before returning.
348 * This function may be called from IRQ context.
350 void disable_irq_nosync(unsigned int irq
)
352 struct irq_desc
*desc
= irq_to_desc(irq
);
359 raw_spin_lock_irqsave(&desc
->lock
, flags
);
360 __disable_irq(desc
, irq
, false);
361 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
362 chip_bus_sync_unlock(desc
);
364 EXPORT_SYMBOL(disable_irq_nosync
);
367 * disable_irq - disable an irq and wait for completion
368 * @irq: Interrupt to disable
370 * Disable the selected interrupt line. Enables and Disables are
372 * This function waits for any pending IRQ handlers for this interrupt
373 * to complete before returning. If you use this function while
374 * holding a resource the IRQ handler may need you will deadlock.
376 * This function may be called - with care - from IRQ context.
378 void disable_irq(unsigned int irq
)
380 struct irq_desc
*desc
= irq_to_desc(irq
);
385 disable_irq_nosync(irq
);
387 synchronize_irq(irq
);
389 EXPORT_SYMBOL(disable_irq
);
391 void __enable_irq(struct irq_desc
*desc
, unsigned int irq
, bool resume
)
394 if (!(desc
->istate
& IRQS_SUSPENDED
)) {
397 if (!(desc
->action
->flags
& IRQF_FORCE_RESUME
))
399 /* Pretend that it got disabled ! */
402 desc
->istate
&= ~IRQS_SUSPENDED
;
405 switch (desc
->depth
) {
408 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n", irq
);
411 if (desc
->istate
& IRQS_SUSPENDED
)
413 /* Prevent probing on this irq: */
414 desc
->status
|= IRQ_NOPROBE
;
416 check_irq_resend(desc
, irq
);
425 * enable_irq - enable handling of an irq
426 * @irq: Interrupt to enable
428 * Undoes the effect of one call to disable_irq(). If this
429 * matches the last disable, processing of interrupts on this
430 * IRQ line is re-enabled.
432 * This function may be called from IRQ context only when
433 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
435 void enable_irq(unsigned int irq
)
437 struct irq_desc
*desc
= irq_to_desc(irq
);
443 if (WARN(!desc
->irq_data
.chip
,
444 KERN_ERR
"enable_irq before setup/request_irq: irq %u\n", irq
))
448 raw_spin_lock_irqsave(&desc
->lock
, flags
);
449 __enable_irq(desc
, irq
, false);
450 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
451 chip_bus_sync_unlock(desc
);
453 EXPORT_SYMBOL(enable_irq
);
455 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
457 struct irq_desc
*desc
= irq_to_desc(irq
);
460 if (desc
->irq_data
.chip
->irq_set_wake
)
461 ret
= desc
->irq_data
.chip
->irq_set_wake(&desc
->irq_data
, on
);
467 * irq_set_irq_wake - control irq power management wakeup
468 * @irq: interrupt to control
469 * @on: enable/disable power management wakeup
471 * Enable/disable power management wakeup mode, which is
472 * disabled by default. Enables and disables must match,
473 * just as they match for non-wakeup mode support.
475 * Wakeup mode lets this IRQ wake the system from sleep
476 * states like "suspend to RAM".
478 int irq_set_irq_wake(unsigned int irq
, unsigned int on
)
480 struct irq_desc
*desc
= irq_to_desc(irq
);
484 /* wakeup-capable irqs can be shared between drivers that
485 * don't need to have the same sleep mode behaviors.
488 raw_spin_lock_irqsave(&desc
->lock
, flags
);
490 if (desc
->wake_depth
++ == 0) {
491 ret
= set_irq_wake_real(irq
, on
);
493 desc
->wake_depth
= 0;
495 desc
->istate
|= IRQS_WAKEUP
;
498 if (desc
->wake_depth
== 0) {
499 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
500 } else if (--desc
->wake_depth
== 0) {
501 ret
= set_irq_wake_real(irq
, on
);
503 desc
->wake_depth
= 1;
505 desc
->istate
&= ~IRQS_WAKEUP
;
509 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
510 chip_bus_sync_unlock(desc
);
513 EXPORT_SYMBOL(irq_set_irq_wake
);
516 * Internal function that tells the architecture code whether a
517 * particular irq has been exclusively allocated or is available
520 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
522 struct irq_desc
*desc
= irq_to_desc(irq
);
523 struct irqaction
*action
;
529 if (desc
->status
& IRQ_NOREQUEST
)
532 raw_spin_lock_irqsave(&desc
->lock
, flags
);
533 action
= desc
->action
;
535 if (irqflags
& action
->flags
& IRQF_SHARED
)
538 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
543 void compat_irq_chip_set_default_handler(struct irq_desc
*desc
)
546 * If the architecture still has not overriden
547 * the flow handler then zap the default. This
548 * should catch incorrect flow-type setting.
550 if (desc
->handle_irq
== &handle_bad_irq
)
551 desc
->handle_irq
= NULL
;
554 int __irq_set_trigger(struct irq_desc
*desc
, unsigned int irq
,
558 struct irq_chip
*chip
= desc
->irq_data
.chip
;
560 if (!chip
|| !chip
->irq_set_type
) {
562 * IRQF_TRIGGER_* but the PIC does not support multiple
565 pr_debug("No set_type function for IRQ %d (%s)\n", irq
,
566 chip
? (chip
->name
? : "unknown") : "unknown");
570 flags
&= IRQ_TYPE_SENSE_MASK
;
571 /* caller masked out all except trigger mode flags */
572 ret
= chip
->irq_set_type(&desc
->irq_data
, flags
);
575 case IRQ_SET_MASK_OK
:
576 irqd_clear(&desc
->irq_data
, IRQD_TRIGGER_MASK
);
577 irqd_set(&desc
->irq_data
, flags
);
579 case IRQ_SET_MASK_OK_NOCOPY
:
580 flags
= irqd_get_trigger_type(&desc
->irq_data
);
581 irq_settings_set_trigger_mask(desc
, flags
);
582 irqd_clear(&desc
->irq_data
, IRQD_LEVEL
);
583 irq_settings_clr_level(desc
);
584 if (flags
& IRQ_TYPE_LEVEL_MASK
) {
585 irq_settings_set_level(desc
);
586 irqd_set(&desc
->irq_data
, IRQD_LEVEL
);
589 if (chip
!= desc
->irq_data
.chip
)
590 irq_chip_set_defaults(desc
->irq_data
.chip
);
593 pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
594 flags
, irq
, chip
->irq_set_type
);
600 * Default primary interrupt handler for threaded interrupts. Is
601 * assigned as primary handler when request_threaded_irq is called
602 * with handler == NULL. Useful for oneshot interrupts.
604 static irqreturn_t
irq_default_primary_handler(int irq
, void *dev_id
)
606 return IRQ_WAKE_THREAD
;
610 * Primary handler for nested threaded interrupts. Should never be
613 static irqreturn_t
irq_nested_primary_handler(int irq
, void *dev_id
)
615 WARN(1, "Primary handler called for nested irq %d\n", irq
);
619 static int irq_wait_for_interrupt(struct irqaction
*action
)
621 while (!kthread_should_stop()) {
622 set_current_state(TASK_INTERRUPTIBLE
);
624 if (test_and_clear_bit(IRQTF_RUNTHREAD
,
625 &action
->thread_flags
)) {
626 __set_current_state(TASK_RUNNING
);
635 * Oneshot interrupts keep the irq line masked until the threaded
636 * handler finished. unmask if the interrupt has not been disabled and
639 static void irq_finalize_oneshot(unsigned int irq
, struct irq_desc
*desc
)
643 raw_spin_lock_irq(&desc
->lock
);
646 * Implausible though it may be we need to protect us against
647 * the following scenario:
649 * The thread is faster done than the hard interrupt handler
650 * on the other CPU. If we unmask the irq line then the
651 * interrupt can come in again and masks the line, leaves due
652 * to IRQS_INPROGRESS and the irq line is masked forever.
654 if (unlikely(desc
->istate
& IRQS_INPROGRESS
)) {
655 raw_spin_unlock_irq(&desc
->lock
);
656 chip_bus_sync_unlock(desc
);
661 if (!(desc
->istate
& IRQS_DISABLED
) && (desc
->istate
& IRQS_MASKED
)) {
662 irq_compat_clr_masked(desc
);
663 desc
->istate
&= ~IRQS_MASKED
;
664 desc
->irq_data
.chip
->irq_unmask(&desc
->irq_data
);
666 raw_spin_unlock_irq(&desc
->lock
);
667 chip_bus_sync_unlock(desc
);
672 * Check whether we need to change the affinity of the interrupt thread.
675 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
)
679 if (!test_and_clear_bit(IRQTF_AFFINITY
, &action
->thread_flags
))
683 * In case we are out of memory we set IRQTF_AFFINITY again and
684 * try again next time
686 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
687 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
691 raw_spin_lock_irq(&desc
->lock
);
692 cpumask_copy(mask
, desc
->irq_data
.affinity
);
693 raw_spin_unlock_irq(&desc
->lock
);
695 set_cpus_allowed_ptr(current
, mask
);
696 free_cpumask_var(mask
);
700 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
) { }
704 * Interrupt handler thread
706 static int irq_thread(void *data
)
708 static const struct sched_param param
= {
709 .sched_priority
= MAX_USER_RT_PRIO
/2,
711 struct irqaction
*action
= data
;
712 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
713 int wake
, oneshot
= desc
->istate
& IRQS_ONESHOT
;
715 sched_setscheduler(current
, SCHED_FIFO
, ¶m
);
716 current
->irqaction
= action
;
718 while (!irq_wait_for_interrupt(action
)) {
720 irq_thread_check_affinity(desc
, action
);
722 atomic_inc(&desc
->threads_active
);
724 raw_spin_lock_irq(&desc
->lock
);
725 if (unlikely(desc
->istate
& IRQS_DISABLED
)) {
727 * CHECKME: We might need a dedicated
728 * IRQ_THREAD_PENDING flag here, which
729 * retriggers the thread in check_irq_resend()
730 * but AFAICT IRQS_PENDING should be fine as it
731 * retriggers the interrupt itself --- tglx
733 irq_compat_set_pending(desc
);
734 desc
->istate
|= IRQS_PENDING
;
735 raw_spin_unlock_irq(&desc
->lock
);
737 raw_spin_unlock_irq(&desc
->lock
);
739 action
->thread_fn(action
->irq
, action
->dev_id
);
742 irq_finalize_oneshot(action
->irq
, desc
);
745 wake
= atomic_dec_and_test(&desc
->threads_active
);
747 if (wake
&& waitqueue_active(&desc
->wait_for_threads
))
748 wake_up(&desc
->wait_for_threads
);
752 * Clear irqaction. Otherwise exit_irq_thread() would make
753 * fuzz about an active irq thread going into nirvana.
755 current
->irqaction
= NULL
;
760 * Called from do_exit()
762 void exit_irq_thread(void)
764 struct task_struct
*tsk
= current
;
770 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
771 tsk
->comm
? tsk
->comm
: "", tsk
->pid
, tsk
->irqaction
->irq
);
774 * Set the THREAD DIED flag to prevent further wakeups of the
775 * soon to be gone threaded handler.
777 set_bit(IRQTF_DIED
, &tsk
->irqaction
->flags
);
781 * Internal function to register an irqaction - typically used to
782 * allocate special interrupts that are part of the architecture.
785 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
787 struct irqaction
*old
, **old_ptr
;
788 const char *old_name
= NULL
;
790 int ret
, nested
, shared
= 0;
796 if (desc
->irq_data
.chip
== &no_irq_chip
)
799 * Some drivers like serial.c use request_irq() heavily,
800 * so we have to be careful not to interfere with a
803 if (new->flags
& IRQF_SAMPLE_RANDOM
) {
805 * This function might sleep, we want to call it first,
806 * outside of the atomic block.
807 * Yes, this might clear the entropy pool if the wrong
808 * driver is attempted to be loaded, without actually
809 * installing a new handler, but is this really a problem,
810 * only the sysadmin is able to do this.
812 rand_initialize_irq(irq
);
815 /* Oneshot interrupts are not allowed with shared */
816 if ((new->flags
& IRQF_ONESHOT
) && (new->flags
& IRQF_SHARED
))
820 * Check whether the interrupt nests into another interrupt
823 nested
= desc
->status
& IRQ_NESTED_THREAD
;
828 * Replace the primary handler which was provided from
829 * the driver for non nested interrupt handling by the
830 * dummy function which warns when called.
832 new->handler
= irq_nested_primary_handler
;
836 * Create a handler thread when a thread function is supplied
837 * and the interrupt does not nest into another interrupt
840 if (new->thread_fn
&& !nested
) {
841 struct task_struct
*t
;
843 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
848 * We keep the reference to the task struct even if
849 * the thread dies to avoid that the interrupt code
850 * references an already freed task_struct.
856 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
862 * The following block of code has to be executed atomically
864 raw_spin_lock_irqsave(&desc
->lock
, flags
);
865 old_ptr
= &desc
->action
;
869 * Can't share interrupts unless both agree to and are
870 * the same type (level, edge, polarity). So both flag
871 * fields must have IRQF_SHARED set and the bits which
872 * set the trigger type must match.
874 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
875 ((old
->flags
^ new->flags
) & IRQF_TRIGGER_MASK
)) {
876 old_name
= old
->name
;
880 /* All handlers must agree on per-cpuness */
881 if ((old
->flags
& IRQF_PERCPU
) !=
882 (new->flags
& IRQF_PERCPU
))
885 /* add new interrupt at end of irq queue */
887 old_ptr
= &old
->next
;
894 irq_chip_set_defaults(desc
->irq_data
.chip
);
896 init_waitqueue_head(&desc
->wait_for_threads
);
898 /* Setup the type (level, edge polarity) if configured: */
899 if (new->flags
& IRQF_TRIGGER_MASK
) {
900 ret
= __irq_set_trigger(desc
, irq
,
901 new->flags
& IRQF_TRIGGER_MASK
);
906 compat_irq_chip_set_default_handler(desc
);
908 desc
->istate
&= ~(IRQS_AUTODETECT
| IRQS_SPURIOUS_DISABLED
| \
909 IRQS_INPROGRESS
| IRQS_ONESHOT
| \
912 if (new->flags
& IRQF_PERCPU
) {
913 irqd_set(&desc
->irq_data
, IRQD_PER_CPU
);
914 irq_settings_set_per_cpu(desc
);
917 if (new->flags
& IRQF_ONESHOT
)
918 desc
->istate
|= IRQS_ONESHOT
;
920 if (!(desc
->status
& IRQ_NOAUTOEN
))
923 /* Undo nested disables: */
926 /* Exclude IRQ from balancing if requested */
927 if (new->flags
& IRQF_NOBALANCING
) {
928 irq_settings_set_no_balancing(desc
);
929 irqd_set(&desc
->irq_data
, IRQD_NO_BALANCING
);
932 /* Set default affinity mask once everything is setup */
933 setup_affinity(irq
, desc
, mask
);
935 } else if (new->flags
& IRQF_TRIGGER_MASK
) {
936 unsigned int nmsk
= new->flags
& IRQF_TRIGGER_MASK
;
937 unsigned int omsk
= irq_settings_get_trigger_mask(desc
);
940 /* hope the handler works with current trigger mode */
941 pr_warning("IRQ %d uses trigger mode %u; requested %u\n",
948 /* Reset broken irq detection when installing new handler */
950 desc
->irqs_unhandled
= 0;
953 * Check whether we disabled the irq via the spurious handler
954 * before. Reenable it and give it another chance.
956 if (shared
&& (desc
->istate
& IRQS_SPURIOUS_DISABLED
)) {
957 desc
->istate
&= ~IRQS_SPURIOUS_DISABLED
;
958 __enable_irq(desc
, irq
, false);
961 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
964 * Strictly no need to wake it up, but hung_task complains
965 * when no hard interrupt wakes the thread up.
968 wake_up_process(new->thread
);
970 register_irq_proc(irq
, desc
);
972 register_handler_proc(irq
, new);
977 #ifdef CONFIG_DEBUG_SHIRQ
978 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
979 printk(KERN_ERR
"IRQ handler type mismatch for IRQ %d\n", irq
);
981 printk(KERN_ERR
"current handler: %s\n", old_name
);
988 free_cpumask_var(mask
);
991 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
993 struct task_struct
*t
= new->thread
;
996 if (likely(!test_bit(IRQTF_DIED
, &new->thread_flags
)))
1004 * setup_irq - setup an interrupt
1005 * @irq: Interrupt line to setup
1006 * @act: irqaction for the interrupt
1008 * Used to statically setup interrupts in the early boot process.
1010 int setup_irq(unsigned int irq
, struct irqaction
*act
)
1013 struct irq_desc
*desc
= irq_to_desc(irq
);
1015 chip_bus_lock(desc
);
1016 retval
= __setup_irq(irq
, desc
, act
);
1017 chip_bus_sync_unlock(desc
);
1021 EXPORT_SYMBOL_GPL(setup_irq
);
1024 * Internal function to unregister an irqaction - used to free
1025 * regular and special interrupts that are part of the architecture.
1027 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
1029 struct irq_desc
*desc
= irq_to_desc(irq
);
1030 struct irqaction
*action
, **action_ptr
;
1031 unsigned long flags
;
1033 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
1038 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1041 * There can be multiple actions per IRQ descriptor, find the right
1042 * one based on the dev_id:
1044 action_ptr
= &desc
->action
;
1046 action
= *action_ptr
;
1049 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1050 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1055 if (action
->dev_id
== dev_id
)
1057 action_ptr
= &action
->next
;
1060 /* Found it - now remove it from the list of entries: */
1061 *action_ptr
= action
->next
;
1063 /* Currently used only by UML, might disappear one day: */
1064 #ifdef CONFIG_IRQ_RELEASE_METHOD
1065 if (desc
->irq_data
.chip
->release
)
1066 desc
->irq_data
.chip
->release(irq
, dev_id
);
1069 /* If this was the last handler, shut down the IRQ line: */
1074 /* make sure affinity_hint is cleaned up */
1075 if (WARN_ON_ONCE(desc
->affinity_hint
))
1076 desc
->affinity_hint
= NULL
;
1079 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1081 unregister_handler_proc(irq
, action
);
1083 /* Make sure it's not being used on another CPU: */
1084 synchronize_irq(irq
);
1086 #ifdef CONFIG_DEBUG_SHIRQ
1088 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1089 * event to happen even now it's being freed, so let's make sure that
1090 * is so by doing an extra call to the handler ....
1092 * ( We do this after actually deregistering it, to make sure that a
1093 * 'real' IRQ doesn't run in * parallel with our fake. )
1095 if (action
->flags
& IRQF_SHARED
) {
1096 local_irq_save(flags
);
1097 action
->handler(irq
, dev_id
);
1098 local_irq_restore(flags
);
1102 if (action
->thread
) {
1103 if (!test_bit(IRQTF_DIED
, &action
->thread_flags
))
1104 kthread_stop(action
->thread
);
1105 put_task_struct(action
->thread
);
1112 * remove_irq - free an interrupt
1113 * @irq: Interrupt line to free
1114 * @act: irqaction for the interrupt
1116 * Used to remove interrupts statically setup by the early boot process.
1118 void remove_irq(unsigned int irq
, struct irqaction
*act
)
1120 __free_irq(irq
, act
->dev_id
);
1122 EXPORT_SYMBOL_GPL(remove_irq
);
1125 * free_irq - free an interrupt allocated with request_irq
1126 * @irq: Interrupt line to free
1127 * @dev_id: Device identity to free
1129 * Remove an interrupt handler. The handler is removed and if the
1130 * interrupt line is no longer in use by any driver it is disabled.
1131 * On a shared IRQ the caller must ensure the interrupt is disabled
1132 * on the card it drives before calling this function. The function
1133 * does not return until any executing interrupts for this IRQ
1136 * This function must not be called from interrupt context.
1138 void free_irq(unsigned int irq
, void *dev_id
)
1140 struct irq_desc
*desc
= irq_to_desc(irq
);
1146 if (WARN_ON(desc
->affinity_notify
))
1147 desc
->affinity_notify
= NULL
;
1150 chip_bus_lock(desc
);
1151 kfree(__free_irq(irq
, dev_id
));
1152 chip_bus_sync_unlock(desc
);
1154 EXPORT_SYMBOL(free_irq
);
1157 * request_threaded_irq - allocate an interrupt line
1158 * @irq: Interrupt line to allocate
1159 * @handler: Function to be called when the IRQ occurs.
1160 * Primary handler for threaded interrupts
1161 * If NULL and thread_fn != NULL the default
1162 * primary handler is installed
1163 * @thread_fn: Function called from the irq handler thread
1164 * If NULL, no irq thread is created
1165 * @irqflags: Interrupt type flags
1166 * @devname: An ascii name for the claiming device
1167 * @dev_id: A cookie passed back to the handler function
1169 * This call allocates interrupt resources and enables the
1170 * interrupt line and IRQ handling. From the point this
1171 * call is made your handler function may be invoked. Since
1172 * your handler function must clear any interrupt the board
1173 * raises, you must take care both to initialise your hardware
1174 * and to set up the interrupt handler in the right order.
1176 * If you want to set up a threaded irq handler for your device
1177 * then you need to supply @handler and @thread_fn. @handler ist
1178 * still called in hard interrupt context and has to check
1179 * whether the interrupt originates from the device. If yes it
1180 * needs to disable the interrupt on the device and return
1181 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1182 * @thread_fn. This split handler design is necessary to support
1183 * shared interrupts.
1185 * Dev_id must be globally unique. Normally the address of the
1186 * device data structure is used as the cookie. Since the handler
1187 * receives this value it makes sense to use it.
1189 * If your interrupt is shared you must pass a non NULL dev_id
1190 * as this is required when freeing the interrupt.
1194 * IRQF_SHARED Interrupt is shared
1195 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
1196 * IRQF_TRIGGER_* Specify active edge(s) or level
1199 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
1200 irq_handler_t thread_fn
, unsigned long irqflags
,
1201 const char *devname
, void *dev_id
)
1203 struct irqaction
*action
;
1204 struct irq_desc
*desc
;
1208 * Sanity-check: shared interrupts must pass in a real dev-ID,
1209 * otherwise we'll have trouble later trying to figure out
1210 * which interrupt is which (messes up the interrupt freeing
1213 if ((irqflags
& IRQF_SHARED
) && !dev_id
)
1216 desc
= irq_to_desc(irq
);
1220 if (desc
->status
& IRQ_NOREQUEST
)
1226 handler
= irq_default_primary_handler
;
1229 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1233 action
->handler
= handler
;
1234 action
->thread_fn
= thread_fn
;
1235 action
->flags
= irqflags
;
1236 action
->name
= devname
;
1237 action
->dev_id
= dev_id
;
1239 chip_bus_lock(desc
);
1240 retval
= __setup_irq(irq
, desc
, action
);
1241 chip_bus_sync_unlock(desc
);
1246 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1247 if (!retval
&& (irqflags
& IRQF_SHARED
)) {
1249 * It's a shared IRQ -- the driver ought to be prepared for it
1250 * to happen immediately, so let's make sure....
1251 * We disable the irq to make sure that a 'real' IRQ doesn't
1252 * run in parallel with our fake.
1254 unsigned long flags
;
1257 local_irq_save(flags
);
1259 handler(irq
, dev_id
);
1261 local_irq_restore(flags
);
1267 EXPORT_SYMBOL(request_threaded_irq
);
1270 * request_any_context_irq - allocate an interrupt line
1271 * @irq: Interrupt line to allocate
1272 * @handler: Function to be called when the IRQ occurs.
1273 * Threaded handler for threaded interrupts.
1274 * @flags: Interrupt type flags
1275 * @name: An ascii name for the claiming device
1276 * @dev_id: A cookie passed back to the handler function
1278 * This call allocates interrupt resources and enables the
1279 * interrupt line and IRQ handling. It selects either a
1280 * hardirq or threaded handling method depending on the
1283 * On failure, it returns a negative value. On success,
1284 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1286 int request_any_context_irq(unsigned int irq
, irq_handler_t handler
,
1287 unsigned long flags
, const char *name
, void *dev_id
)
1289 struct irq_desc
*desc
= irq_to_desc(irq
);
1295 if (desc
->status
& IRQ_NESTED_THREAD
) {
1296 ret
= request_threaded_irq(irq
, NULL
, handler
,
1297 flags
, name
, dev_id
);
1298 return !ret
? IRQC_IS_NESTED
: ret
;
1301 ret
= request_irq(irq
, handler
, flags
, name
, dev_id
);
1302 return !ret
? IRQC_IS_HARDIRQ
: ret
;
1304 EXPORT_SYMBOL_GPL(request_any_context_irq
);